Precisely Guided Phototherapy Apparatus

ABSTRACT

A precisely guided phototherapy apparatus for treating soft tissue injury, chronic pain, and promoting wound healing for both human and animal targets. The phototherapy apparatus comprises sensor means for monitoring the intensity, position, and movement of the therapeutic light beam over the treatment area. The delivered light energy dosage is determined accordingly based on these parameters. The phototherapy apparatus further comprises a projector device for projecting markers on top of the treatment area. The markers represent the values of the delivered light energy dosage for assisting the practitioner or clinician in precisely controlling the phototherapy procedure.

REFERENCE TO RELATED APPLICATION

This application claims an invention which was disclosed in ProvisionalPatent Application No. 61/309,671, filed Mar. 02, 2010, entitled“PRECISELY GUIDED PHOTOTHERAPY APPARATUS”. The benefit under 35 USC§119(e) of the above mentioned United States Provisional Applications ishereby claimed, and the aforementioned application is herebyincorporated herein by reference.

FIELD OF THE INVENTION

This invention generally relates to a phototherapy apparatus, and morespecifically to a precisely guided phototherapy apparatus.

BACKGROUND

Phototherapy is a medical and veterinary technique which uses lasers,light emitting diodes (LEDs) or other types of light sources tostimulate or inhibit cellular function. Recently, this technique hasbeen widely used for treating soft tissue injury, chronic pain, andpromoting wound healing for both human and animal targets.

Typically, the phototherapy procedure involves radiating light energy inthe ultraviolet (UV), visible, or infrared wavelength onto or into thepatient's skin. It is highly desirable to precisely control the dose oflight energy that is applied on a specific treatment area to achieve anoptimum therapeutic effect. However, none of the existing phototherapyapparatus could fulfill this task due to the following reasons. First,the therapeutic light generally has a non-uniform beam profile, i.e. thelight intensity varies significantly from the center to the edge of thelight beam. Thus the treatment area inevitably receives uneven energydosages. Second, some therapeutic light (e.g. the infrared light) isinvisible to the human eyes. In these cases, an aiming beam in thevisible wavelength is generally provided to guide the therapeutic light.However, due to their wavelength and power difference, the aiming beamgenerally has an intensity profile different from that of thetherapeutic light, which prevents it from providing precise dosageguidance to the clinician or practitioner. Third, the practitioner orclinician usually needs to scan the therapeutic light beam to cover alarge treatment area, making it even harder to track the exact deliveredenergy dosage for any specific region of the area.

There thus exists a need for an improved phototherapy apparatus, whichcan provide real time monitoring of the delivered light energy dosage onthe subject surface of the patient for assisting the practitioner orclinician in precisely controlling the phototherapy procedure.

SUMMARY OF THE INVENTION

It is the overall goal of the present invention to solve the abovementioned problems and provide a precisely guided phototherapyapparatus. The phototherapy apparatus comprises sensor means formonitoring the intensity, position, and movement of the therapeuticlight beam over the treatment area. The delivered light energy dosage isdetermined accordingly based on these parameters. The phototherapyapparatus further comprises a projector device for projecting markers ontop of the treatment area. The markers represent the values of thedelivered light energy dosage for assisting the practitioner orclinician in precisely controlling the phototherapy procedure.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying figures, where like reference numerals refer toidentical or functionally similar elements throughout the separate viewsand which together with the detailed description below are incorporatedin and form part of the specification, serve to further illustratevarious embodiments and to explain various principles and advantages allin accordance with the present invention.

FIG. 1 illustrates one exemplary embodiment of the precisely guidedphototherapy apparatus.

Skilled artisans will appreciate that elements in the figures areillustrated for simplicity and clarity and have not necessarily beendrawn to scale. For example, the dimensions of some of the elements inthe figures may be exaggerated relative to other elements to help toimprove understanding of embodiments of the present invention.

DETAILED DESCRIPTION

Before describing in detail embodiments that are in accordance with thepresent invention, it should be observed that the embodiments resideprimarily in combinations of method steps and apparatus componentsrelated to a precisely guided phototherapy apparatus. Accordingly, theapparatus components and method steps have been represented whereappropriate by conventional symbols in the drawings, showing only thosespecific details that are pertinent to understanding the embodiments ofthe present invention so as not to obscure the disclosure with detailsthat will be readily apparent to those of ordinary skill in the arthaving the benefit of the description herein.

In this document, relational terms such as first and second, top andbottom, and the like may be used solely to distinguish one entity oraction from another entity or action without necessarily requiring orimplying any actual such relationship or order between such entities oractions. The terms “comprises,” “comprising,” or any other variationthereof, are intended to cover a non-exclusive inclusion, such that aprocess, method, article, or apparatus that comprises a list of elementsdoes not include only those elements but may include other elements notexpressly listed or inherent to such process, method, article, orapparatus. An element proceeded by “comprises . . . a” does not, withoutmore constraints, preclude the existence of additional identicalelements in the process, method, article, or apparatus that comprisesthe element.

FIG. 1 illustrates one exemplary embodiment of the precisely guidedphototherapy apparatus. Here the light source module 100 of thephototherapy apparatus comprises a high power diode laser operating at anear infrared wavelength of 980 nm. The output power of the diode laseris adjustable in the range of 0.5-15 watts for producing photochemicalreaction, e.g. up-regulation and down-regulation of adenosinetriphosphate (ATP), reactive oxygen species, and nitric oxide in thesubject biological tissue 106. The photochemical reaction in turnproduces the following therapeutic effects: (i) stimulating white bloodcell activity; (ii) accelerating macrophage activity, growth factorsecretion and collagen synthesis; (iii) promoting revascularization andmicro-circulation; (iv) increasing fibroblast numbers and collagenproduction; (v) accelerating epithelial cell regeneration and speedingup wound healing; (vi) increasing growth-phase-specific DNA synthesis;(vii) stimulating higher activity in cell proliferation anddifferentiation; (viii) increasing the intra and inter-molecularhydrogen bonding. All these therapeutic effects combine to benefit thesubject biological tissue 106.

Referring to FIG. 1, the phototherapy apparatus comprises an opticalfiber 102 and an output wand 104 for delivering the laser light from thelight source module 100 onto the surface of the subject biologicaltissue 106. The laser light 120 is absorbed by the chromophores (e.g.water, melanin, hemoglobin) of the biological tissue to trigger theabove disclosed photochemical reactions. The phototherapy apparatusfurther comprises an image sensor 108, e.g. a CCD or CMOS image sensorfor capturing successive images of the subject surface. These imagesrecord the position and intensity profile of the therapeutic light onthe surface of the biological tissue 106. Variations between successiveimages are processed by an image processing unit (not shown) andtranslated into movement of the therapeutic light beam over thetreatment area. Based on the recorded intensity, position, and movementinformation of the therapeutic light beam, the delivered light energydosage for each specific region of the treatment area (hence an energydosage distribution) is determined. Through connection 112, the energydosage distribution information is transmitted to a digital lightprojector 110, e.g. a DLP (digital light processing), LCD (liquidcrystal display) or LCOS (liquid crystal on silicon) projector, whichprojects corresponding markers 114 onto the surface of the biologicaltissue. The markers 114 can be numeral values or colored graphicsrepresenting the delivered light energy dosage. For example, a greencolor may represent an energy dosage within an appropriate range, whilea yellow color and a red color may represent energy dosages below andabove appropriate level, respectively. The practitioner or clinician canprecisely control the phototherapy procedure based on the guidance ofthe projected markers 114.

In this exemplary embodiment, the output wand 104 and the projector 110share the same optical path with their output light beams combined by abeam combiner 118 (e.g. a dichroic beam combiner). Thus the projectedmarkers 114 coincide with the laser beam 120 on the subject surface. Thedigital light projector 110 may further project a visible image of theintensity profile of the laser beam 120 (e.g. a contour image withdifferent intensity levels displayed in different colors) onto thesurface of the biological tissue 106. The visible image coincides withthe infrared laser beam such that its intensity, position, and movementare revealed to the practitioner or clinician. The values of theintensity profile, as well as the energy dosage distribution, can bedisplayed on top of the visible image. A plurality of grids 116, eitherin the form of a transparent grid paper, or projected lines from thelight projector 110, may be introduced on top of the subject surface tofacilitate tracking of the therapeutic light beam. The output wand 104,the image sensor 108, and the light projector 110 of the presentembodiment can be integrated together to form a commonoutputting/sensing/projecting port for the phototherapy apparatus.Before the phototherapy procedure, the light projector 110 may display asimulated or pre-recorded laser beam profile in accordance to theselected laser parameters (e.g. output power of the laser, distance fromthe output wand to the tissue), which assists the practitioner/clinicianin optimizing the treatment procedure.

In a simplified variation of the present embodiment, the digital lightprojector 110 may be replaced with a laser or LED pointer, whichprojects different colored light onto the subject surface. The colorvaries in accordance to the delivered light energy dosage for assistingthe practitioner/clinician with energy dosage control. The image sensor108 may be replaced with a plurality of photo detectors for recordingthe intensity, position, and movement of the therapeutic light beam.Alternatively, the position and movement of the output wand 104 (hencethe position and movement of the therapeutic light beam) can be trackedwith other types of sensors, such as thermal, mechanical, electrical,magnetic, or acoustic sensors.

In another variation of the present embodiment, the phototherapyapparatus further comprises a temperature sensor, preferably in the formof a non-contact infrared temperature sensor for monitoring thetemperature of the subject biological tissue. Through the lightprojector, the measured temperature value is projected onto the surfaceof the biological tissue as a means to control the light energy dosage.

In yet another variation of the present embodiment, the phototherapyapparatus may comprise multiple laser sources with different outputwavelengths to treat biological tissues with different type andconcentration of chromophores. The outputs of the multiple laser sourcescan be combined at adjustable proportions and simultaneously applied tothe biological tissue to achieve an enhanced treatment result. The lasersources may operate in a pulsed mode such that a high peak power isproduced to increase the penetration depth of the laser light and/or totrigger nonlinear photochemical reactions yet the average power of thelaser light is maintained at low levels to avoid any tissue damage.

The disclosed phototherapy apparatus can be used in other fields aswell, such as photo-dynamic therapy, where the light source is used toactivate a photosensitizing drug, or in aesthetic treatments such asacne treatment, wrinkle removal, skin-tightening, etc.

In the foregoing specification, specific embodiments of the presentinvention have been described. However, one of ordinary skill in the artappreciates that various modifications and changes can be made withoutdeparting from the scope of the present invention as set forth in theclaims below. The numerical values cited in the specific embodiment areillustrative rather than limiting. Accordingly, the specification andfigures are to be regarded in an illustrative rather than a restrictivesense, and all such modifications are intended to be included within thescope of present invention. The benefits, advantages, solutions toproblems, and any element(s) that may cause any benefit, advantage, orsolution to occur or become more pronounced are not to be construed as acritical, required, or essential features or elements of any or all theclaims. The invention is defined solely by the appended claims includingany amendments made during the pendency of this application and allequivalents of those claims as issued.

1. A phototherapy apparatus for treating biological tissue, saidphototherapy apparatus comprising: at least one light source forproducing therapeutic light; light delivery means for delivering saidtherapeutic light onto a surface of the biological tissue; sensor meansfor monitoring intensity, position, and movement of said therapeuticlight over the surface of the biological tissue and determining adelivered light energy dosage; and a projector device for projectingmarkers onto the surface of the biological tissue, said markersrepresenting values of said delivered light energy dosage.
 2. Thephototherapy apparatus of claim 1, wherein said markers comprisenumerals.
 3. The phototherapy apparatus of claim 1, wherein said markerscomprise graphics.
 4. The phototherapy apparatus of claim 1, whereinsaid markers have different colors.
 5. The phototherapy apparatus ofclaim 1, wherein said sensor means comprise optical, thermal,mechanical, electrical, magnetic, or acoustic sensors.
 6. Thephototherapy apparatus of claim 1, wherein said sensor means comprise animage sensor.
 7. The phototherapy apparatus of claim 6, wherein saidimage sensor comprises a CCD or CMOS image sensor.
 8. The phototherapyapparatus of claim 1, wherein said at least one light source comprises anear infrared laser.
 9. The phototherapy apparatus of claim 1, whereinsaid at least one light source comprises a visible laser.
 10. Thephototherapy apparatus of claim 1, wherein said at least one lightsource comprises an ultraviolet laser.
 11. The phototherapy apparatus ofclaim 1, wherein said projector device comprises a digital lightprojector.
 12. The phototherapy apparatus of claim 1, wherein saidprojector device comprises a laser or light emitting diode (LED)pointer.
 13. The phototherapy apparatus of claim 1, wherein saidprojector device projects a visible image of an intensity profile ofsaid therapeutic light onto the surface of the biological tissue,wherein said visible image coincide with said therapeutic light on thesurface of the biological tissue.
 14. The phototherapy apparatus ofclaim 13, wherein said projector device projects markers on top of saidvisible image, said markers representing values of said intensityprofile.
 15. The phototherapy apparatus of claim 1, further comprising atemperature sensor for measuring a temperature of the biological tissue,wherein said projector device projects markers representing the measuredtemperature value onto the surface of the biological tissue.
 16. Aphototherapy method for treating biological tissue, said phototherapymethod comprising the steps of: providing at least one light source forproducing therapeutic light; delivering said therapeutic light onto asurface of the biological tissue; monitoring intensity, position, andmovement of said therapeutic light over the surface of the biologicaltissue and determining a delivered light energy dosage; and providing aprojector device for projecting markers onto the surface of thebiological tissue, said markers representing values of said deliveredlight energy dosage.